available over the counter: no

uses: control of certain types of  seizures;  often used in conjunction with other anticonvulsants which have failed to control seizures

mechanism of action: mechanism unknown

side effects
• common: drowsiness, dizziness, faigue, anxiety, confusion, depression
• less common: back pain, nausea, vomiting, dry mouth, abdominal pain, hearing difficulty
• serious: kidney stones (pain in the low back)

concerns: do not stop medication abruptly;  taper, per physician over weeks